Multiple-circuit electric switchboard



Dec. 3, 1968 v R. GREENWALL, JR 3,414,696

MULTIPLE-CIRCUIT ELECTRIC SWITCHBOARD Filed Feb. 28, 1967 IN VEN TOR.

ROBERT A.GREENWALL, JR.

United States Patent 3,414,696 MULTIPLE-CIRCUIT ELECTRIC SWITCHBOARD Robert A. Greenwall, Jr., Salt Lake City, Utah, assignor to B. J. Management Corporation, Salt Lake City, Utah,

a corporation of Utah Filed Feb. 28, 1967, Ser. No. 619,350 Claims. (Cl. 200168) ABSTRACT OF THE DISCLOSURE A multiple-circuit switchboard of the type wherein conductive bars are fitted into respective slots of a series of mutually parallel slots in the surface of an insulative base for traversal and selective contact by movable switch means in closing selected electrical circuits. The conductive bars are of strap-like configuration and are mounted edge-wise within the respective slots, with their top edges aligned in coplanar relationship. To provide most advantageously for connection with respective electrical circuits, the ends of successive conductive bars are preferably extended outwardly from the insulative base angularly from the plane of the aligned top edges so that such ends at a given side of such base are directed oppositely and are, thus, widely separated. To effectively support longitudinal strip portions of a longitudinally slotted front panel, that is customarily provided for guiding the respective movable switch means in this type of switchboard, longitudinal plates are preferably provided between such strip portions and the insulative base, and tongues, depending from some of such plates, are preferably provided for releasable fastening to a base frame so as to retain the front panel and insulative base in position.

The present invention relates to multiple-circuit switchboard constructions and, more particularly, to improvements therein which will give to an over-all panel construction marked flexibility, high current-carrying capacity, accommodation of maximum potential diiferences relatives to a plurality of conductive bars disposed in a minimum amount of space, rigidity in front panel construction, not withstanding extent-of-travel-slots for movable switch means used in connecting selected circuits of the multiple circuits provided by the switchboard and other advantages which will be hereinafter enumerated.

A pioneer patent (owned by the assignee of the present invention), concerning practical constructions for switchboards providing multiple electrical connections is the Ariel R. Davis patent, US. Patent No. Re. 24,586. The present invention represents a further advance in this field in a number of particulars. In the first place, the conductive bars recessed into the insulative base of the present invention take a strap-like, rectangular configuration. In this way, the current carrying capacity of the conductive bars is increased; yet, the spacing between conductive bars may be substantially reduced over present constructions. An additional feature present in the invention is the manner of securement of these conductive bars, of strap-configurement or rectangular cross-section, to the insulative base to which they are mounted. A further advantage is present in the configuration of the conductive bars in the switchboard structure, wherein the terminal ends thereof are staggered in position so as to increase the air-resistance distance between adjacent terminal extremities. This enables the conductive bar portion of the system to accommodate high potential differences, if needed, between adjacent conductive bars. Further advantages in the present invention, as will be pointed out, reside in the almost infinite number of circuits that can be accommodated by the system. Heretofore, the

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number of circuits that might be utilized was restricted by the fact that several portions of the front panel of the switchboard would tend to either sag or bow outwardly at those portions between the necessarily-included travel slots in the outer panel. By the present invention these central areas are supported and/ or retained between slots so that the front panel and hence the switchboard can be of almost any desired length. Hence, the quick-connect devices (i.e. moveable switch means) employed can be used to connect one or more input circuits to almost an infinite number of output circuits, or vice versa.

Accordingly, a principal object of the present invention is to provide a new and improved multiple circuit switchboard.

An additional object is to provide, in a switchboard of the type described, an insulative base having a plurality of mutually-spaced, conductive bars, the latter being of such cross-section and configuration as to provide maximum current-carrying capacity for the conductive bars and, additionally, to adapt the switchboard for application thereto of potential differences, as between adjacent conductive bars, of desired maximum degree.

A further object is to provide for a unique insulative base and conductive bar construction wherein sparkquenching chambers are disposed above the upper edges of the individual, strap-like conductive bars, between the top edges thereof and the upper surface of the insulative base.

An additional object is to provide, in the structure mentioned in the aforementioned object paragraph, a means of easily securing conductive bars of rectangular crosssection to and within the slots of insulative bases.

An additional object is to provide means for mounting and/or securing areas of outermost or front switchboard panels, between slot travel paths thereof, to adjacent structures so that the panel areas affected will not tend to bow outwardly or otherwise become deformed.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings in which:

FIGURE 1 is a perspective, exploded view of the switchboard construction utilizing the principles of the present invention.

FIGURE 2 is an enlarged, fragmentary, section view taken along the line 2-2 in FIGURE 1.

FIGURE 3 is an enlarged, fragmentary, section view taken along the line 33 in FIGURE 1.

FIGURE 4 is a fragmentary elevation taken along the line 4-4 in FIGURE 1, wherein the switchboard apparatus as disclosed has been assembled, this to show the engagement condition of the retention portion of the structure to retain portions of the front panel in alignment with the remainder of the panel.

In FIGURE 1 the switchboard panel device 10 includes a panel assembly 11. Panel assembly 11 is substantially the same as that illustrated in the inventors co-pending application entitled, Improved Switching Means for Electrio Switchboards, Serial No. 619,227. The only changes in the present panel assembly are in the configuration of the base 20 and in the series of divider plates 13. Divider plates 13 are secured within corresponding recesses 14 found in the under-side 15 of front panel 16. These divider plates 13 include not only a horizontal elongate principal portion 17, but also a depending leg or retainer tongue 18. The quick-connect switch means 19 may form the same type of device as indicated in FIGURE 2 of the above identified co-pending patent application, for

3 example, or may take the form as shown in the Ariel R. Davis patent, US. Patent No. Re. 24,586.

Of special importance is the configuration of insulative base member 12. The latter forms an integral part of base 20. Insulative base member 12 includes a plurality of transverse slots or recesses 21 into which are fitted the conductive bars or bar portions 22 of respective conductive-bar members 23. Conductive bar members also include, integrally related with conductive bars 22, a respective offset portion 24 and, secured to the latter, a terminal connector portion 25. It will be noted that the offset portions 24 are integrally related with their respective conductive bars 22 and lie, preferably, in respective, mutually parallel planes disposed transversely with respect to insulative base member 12. Terminal connection portions 25 may include a respective box terminal receptacle 26 which is secured by a screw 27 to flange 28 of ofiFset portion 24. A terminal securement lug 29 threadedly engages the box-like terminal portion 26 for securement of the lead therewithin.

The necessity for the inclusion of spark-quenching chambers above the individual conductive bars, relative to the top surface 30 of insulative base member 12, has been described in detail in the Ariel R. Davis Patent No. Re. 24,586. It is at this point that the particular configuration of the conductive bars, together with their securement in the several recesses 21, comes into play. It is important to point out that the transverse, crosssectional configuration of the individual conductive bars has been chosen to be rectangular, that is, of a thin, straplike rectangular shape. See FIGURE 3 in this regard. Such is ideally suited for inclusion in the insulative base construction of the present invention since the same provides more current-carrying capacity for a given slotwidth dimension in the insulative base member 12. For the same current-carrying capacity, a conductor having a round cross-section would have to have an unusually large size. Such would result in some difiiculty and in increasing the expense of manufacture, since the grooves would be circular in cross-section and slotted at their upper extremities as indicated in the Davis Patent No. Re. 24,586. Clearly, high current-carrying capacity bars are easily disposed within an insulative base member 12, as shown in the present invention, in an extremely small and compact space area.

Of course, there is the problem of securing these conductive bar members 23 in their respective insulative base member recesses 21. One manner in which this may be done is simply by the use of an epoxy cement or other cementitious substance at 33 as indicated in FIGURE 1.

Another manner of securement is illustrated by the inclusion of a retention strip 34. The same may include a depending foot 35 taking the form of an elongate rib disposed at the bottom of strip 34. Correspondingly, there may be included in the construction the provision of longitudinal groove 36 which is so cut into the upper surface 30 of insulative base 12 that the bottom thereof at 37 is coplanar with the coplanar, upper or top edges 39 of conductive bars 22. In this way, and as shown in FIGURES 2 and 3, the retention strip 34 may be easily bolted or screwed down by means of attachments 37, The latter threadedly engaging threaded apertures 38 of insulated base 12.

A further and important feature of the present invention is the fact that the terminal ends at 25 are staggered in position by reason of the respective off-set portions 24, as indicated in the lower central portion of FIGURE 1. This provides for the closest possible spacing between the conductive bar members 23, yet permits relatively large terminal connection portions 25 to be used in securing external leads thereto. Much more space, and hence a greater path of air resistance, is supplied between the terminal connections of the plurality of conductive bars, thereby permitting these bars to be operated at greater potential differences than is usually the case.

In returning again to the panel assembly 11 it is seen that the divider plates 13 each include divider tongues 18. This is provided for a definite and an important purpose. Panel 10 is made of insulative material, such as that going under the trade name Bakelite or another resinous material, and by nature Will be deformable. Where the panel tends to bow outwardly, particularly at regions X between adjacent travel slots T, then there can arise some difiiculty in preserving good connections as between the switch means, the rails (see the inventors copending application above referenced) upon which the switch means rides, and so forth. It is important to keep the panel 10 rigid and prevent the same from bowing outwardly. It is for this purpose that the retainer tongues 18 are now provided. The same are formed integrally with the divider plates 13, and the upper edges of the latter are glued by epoxy or other means to the recessed areas 14 formed on the under side of panel 12. Hence, and as concerns the divider plates 13, the tongues 18 may be disposed to pass through receiving slots 39 so as to be disposed such that their apertures 40 may be engaged by tongue retainer pin 41. The latter itself is retained in place by apertures 42 and 43 of base mounting frame 44. Mounting frame 44 may be made of metal and includes rigid central braces 45 and 46. In assembly, a plurality of screws 47, one being shown, will be oriented at the four corners of the structure to be secured through the structure into drilled and tapped apertures 48 of frame 44. In this regard, FIGURE 4 shows the completed structure wherein the divider blades 13 including tongues 18 are positioned in the completely assembled structure such that pin 41 will secure the tongues in the rigid mounting frame 44. Thus, the panel 12, no matter how long or how great the length of the travel slots T, may still be retained so as not to be bowed outwardly.

There are, of course, many equivalent ways in which panels, though made of flexible material, can be held from bowing outwardly at the front panel strip regions, such as at X. The essential feature of the invention is that there be provided means disposed between the travel slots T, and secured to the individual central areas of the panel between the slots, so that such means may be secured and retained to the rigid members, such as frame or support 44, or even to the base 20-.

Accordingly, what the present invention provides are the concepts, and the structures relating thereto, of using easily constructed strap-like bars as conductive elements in the switch panel; in providing spark chambers thereover through securement of such conductive bars within their corresponding slots in an insulative base beneath the upper surface of the latter; and of staggering the terminal ends, preferably in the respective planes Of the respective bars, so that the conductive bars and their terminals may be spaced as closely together in respective, mutually parallel planes so that the maximum of high-voltage circuits can be provided in the minimum panel space. Also included herein is the concept of retaining, by suitable retainer means, the inter-slot portions of the top panel of the switchboard, so that such portions of this panel will not 'have any tendency .whatever to bow outwardly, and this despite the length of the travel slots used for the quick-connect switch devices in the panel construction. As to the latter, a number of equivalent types of supporting means or retainer means can be used to keep panel areas between adjacent panel slots from either sagging or bowing outwardly, as herebefore indicated.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

1 claim:

1. In a multiple-circuit switchboard construction, an insulative base provided with a plurality of parallel slots each having a depth dimension greater than the width dimension thereof; and a plurality of strap-like conductive bars, having co-planarly aligned top edges, mounted edge-wise within respective ones of said parallel slots such that said top edges are disposed beneath that surface of said insulative base proximate thereto.

2. In a multiple-circuit switchboard construction, an insulative base provided with a plurality of parallel slots each having a depth dimension greater than the width dimension thereof; a plurality of strap-like conductive bars, having co-planarly aligned top edges, mounted edgewise within respective ones of said parallel slots such that said top edges are "disposed beneath that surface of said insulative base proximate thereto; and means securing said conductive bars within said insulative base.

3. Structure according to claim 2 wherein said securing means comprises cementitious material disposed within said parallel slots between said conductive bars and said insulative base.

4. Structure according to claim 2, wherein said insulative base is provided with a groove disposed transversely over said parallel slots, said groove having a base and being of a depth such that said insulative base thereof is co-planar with said top edges of said conductive bars, and a retention strip disposed in said groove, and secured to said insulative base for retaining said conductive bars within said parallel slots.

5. Structure according to claim 4 wherein said retention strip includes a longitudinal rib seated in said groove, and attachment means securing said retention strip to said insulative base.

6. In a multiple-circuit switchboard construction, an insulative base provided with a plurality of parallel slots each having a depth dimension greater than the Width dimension thereof; and a plurality of strap-like conductive bars, having co planarly aligned top edges, mounted edge- ,wise within respective ones of said parallel slots; the

ends of successive conductive bars being extended outwardly from said slots and from said insulative base angularly from the plane of said aligned top edges so that successive conductive bar ends at a given side of said insulative base extend in opposite directions and are widely separated; said conductive bar ends being adapted for independent connection with respective electrical circuits.

7. The structure of claim 6, wherein the outwardly extended ends of successive conductive bars are disposed in alternating fashion on opposite sides of said insulative base.

-8. In a multiple-circuit switchboard construction which includes an insulative base, a front panel secured to said insulative base in spaced substantially coextensive relationship therewith and having plural, elongate, travel slots, and switch means operatively and slidea'bly secured to said insulative base and "extending outwardly through said travel slots, the improvement comprising longitudinal plates extending substantially parallel with said slots between and interconnecting said insulative base and portions of said front panel between said slots so as to rigidly support said portions along their lengths against bowing and sagging tendencies.

9. Structure according to claim 8, wherein there are additionally provided tongue means depending from some of said plates, and structural means fastened to said tongue means for retaining said front panel and said insulative base in position.

10. Structure according to claim 9, wherein said structural means includes a base frame positioned below said insulative base, and said tongue means and said base frame include aligned, transverse apertures; and wherein said base frame is releasably fastened to said tongue means by pin means passed through said apertures.

References Cited UNITED STATES PATENTS 3,158,698 11/1964 Campbell 200-468 3,321,601 5/1967 Walterick et al. 200-168 ROBERT K. SCHAEFER, Primary Examiner.

H. O. JONES, Assistant Examiner. 

